Process of road treatment



Patented Nov. 16, 1926.

UNITED STATES PTET orFicE.

PER GosrA EKs'rnoM, or STOCKHOLM, SWEDEN.

PROCESS OF ROAD TREATMENT.

No Drawing.

This invention relates to a process of treating roads and the like and while its object is in the first place to bind the dust, it also purportsto provide the road with a hard and durable wearing surface.

It is well known that dust can be laid by spraying roads and the like with sulphite lye. This method, however, is not quite satisfactory, principally because the substances which serve in the sulphite lye for the binding of the dust, are soluble in water and therefore, after a comparatively short time, get dissolved by rain and other moisture and are washed away.

It has already been proposed to treat roads with a sulphite solution which has been concentrated to a dry powder and whose normal acidity has been reduced to about one half by the addition of lime or other basic material so that it has the property, after being dissolved in water, of be coming more or less insoluble on protracted exposure to air and moisture.

According to the present invention the above-mentioned substances, which are of an organic nature, are fixed all at once and definitely by converting them by an adequate addition of suitable bases into salts which are insoluble in water. This chemi cal reaction may either be carried out on the road itself after the sulphite and the base or bases have been applied to the same, or the chemicals may be mixed and applied together. If t-he'former method is adopted, two watery mixtures are made, one of the sulphite lye and the other of a suitable base, whereupon first one mixture and immediately thereafter the other mixture are ap plied to the road, preferably by spraying. Naturally, both mixtures can be sprayed on simultaneously if suitable devices for this purpose are at hand. Care should be taken that the mixtures are applied in chemically equivalent proportions. With this object in view the two mixtures are from the comnienceinent rendered chemically equivalent, and the proper proportions are applied to each unit area of the road.

In the case of the second method, equivalent proportions of the two solutions are mixed, and the resulting, pasty liquid is spread over the road in any suitable man- YEP Application filed July 6, 1925, Serial No. 41,884, and in Sweden May 22, 1925.

ery and it is used in its original state after its contents of organic substances has been ascertained. The lye may, particularly if it has to betransported some distance, be condensed before the transport and "subsequently thinned out to the proper consistency for use.

By treating roads in this manner, the.

advantage is obtained that, in addition to the binding of the dust in an efiicient and lasting manner, a hard, asphalt-like surface is produced so that the road itself will be considerably improved and rendered more durable.

I claim:

1. A process of treating roads with sulphite lye consisting in applying to the road surface together with the lye a suflicient quantity of bases adapted to react with the lightly as well as strongly acid organic compounds of the lye to form at once with the bulk of such compounds, salts which are insoluble in water.

2. A process of treating roads with sulphite lye, consisting in mixing with the sulphite lye immediately before its application to the road, a sufficient quantity of bases adapted to react with the lightly as well as strongly acid organic compounds of the lye to form at once with the bulk of such compounds, salts which are insoluble in water. i

3. A process of treating roads with sulphite lye consisting in applying to the road surface together with the lye sutlicient limewater to convert at once the lightly as well as strongly acid organic compounds of the lye into salts which are insoluble in water.

sosra nKsrRoM. 

